class Avio:
    def __init__(self, identificador, nfil) :
        self.id = identificador
        self.__places = []
        for i in range(nfil) :
            d = {}.fromkeys(list('ABCDEF'), 'Lliure')
            self.__places.append(d)

    def __len__(self) :
        return len(self.__places)

    def __getitem__(self, pos) :
        return self.__places[pos[0]][pos[1]]
        
    def __setitem__(self, pos, nom) :
        self.__places[pos[0]][pos[1]] = nom